Plants produce microscopic round or oval pollen grains to reproduce. Some plants uses its own pollen and fertilize itself but for others pollen has to be transferred from plant to plant to fertilize them. Insects and wind do this job of transportation. When people who have a pollen allergy inhale the pollen, they get allergy symptoms. it can cause allergy symptoms such as: Sneezing, Watery eyes, Nasal congestion, Runny nose, Itchy throat, Cough, Sore throat, Hoarse voice etc. Hay fever (Allergic Rhinitis) is the most common of the allergic disease due to pollens.